Agile never prescribe methods of doing Risk Analysis. Agile Manifesto says four values and 12 principles. According to these values, you need to figure out various methods like for prioritization, estimation and risk analysis. If your actions are aligned with four values and 12 principles, you are Agile; Agile does not give any prescriptions of doing how to do risk analysis, Because best methods depend on your project context. If a fix prescription is there you are no more Agile.